(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*

This guide provides a more detailed description of the syntax that is supported along with examples.

This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.

Concept Search - What can I type?

For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.

Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.

Publishing Venue

Related People

Abstract

In delta modulation, it is desired to minimize the tracking error between a time varying analog input applied to the modulator and the representative stream of "1's" and "0's" generated therefrom. Delta modulation is a coding process. It requires a periodic sampling of a waveform and comparing the sampled package magnitude with a reference. If a sample value exceeds the reference then a positive signal is generated. If the reference exceeds the sampled magnitude a negative signal is generated. The reference value is, in turn, incremented by a value opposite in phase to that of the modulator output.

Country

United States

Language

English (United States)

This text was extracted from a PDF file.

At least one non-text object (such as an image or picture) has been suppressed.

This is the abbreviated version, containing approximately
52% of the total text.

Page 1 of 3

Apparatus for Decreasing Delta Modulation Distortion

In delta modulation, it is desired to minimize the tracking error between a
time varying analog input applied to the modulator and the representative stream
of "1's" and "0's" generated therefrom. Delta modulation is a coding process. It
requires a periodic sampling of a waveform and comparing the sampled package
magnitude with a reference. If a sample value exceeds the reference then a
positive signal is generated. If the reference exceeds the sampled magnitude a
negative signal is generated. The reference value is, in turn, incremented by a
value opposite in phase to that of the modulator output. It is well appreciated, for
example, that if a stream of successive 1's or 0's were generated, then it could
be concluded that the sampled waveform either always exceeded the reference
value or the reference value always exceeded the sampled value. In either case,
the coder would not be closely tracking the signal.

It is recognized that better tracking can be obtained if it is possible to either
anticipate the trend of the input signal or find the same type of information in the
output of such a system and make adjustments accordingly. As applied to delta
modulators, the prior art has taught that tracking accuracy is improved by
changing the sampling frequency or the step size (the amount of unit change
algebraically added to the reference value each time an output signal is
generated).

Hereinafter, in the described apparatus the delta tracking error can be
minimized by complementing the modulator output bit stream during the ith + 1
time interval, if the error occurring during the ith interval was greater than a unit
step. Because the apparatus monitors the modulator error and inverts the
appropriate pulses in the modulator output bit stream, then it is not necessary to
either modify the sampling frequency or the step size.

Reference is made to Fig. 1 where the feed forward detection
and correction logic for the delta coder tracking error is set forth.

Delta coder 2 is responsive to analog input 1 over path 3 by
generating a binary 1 or 0, i.e., Delta or Delta out from flip-flop 7. Difference amplifier 5 causes flip-flop 7 to generate a Delta out
at each sampled interval when the analog input on line 3 exceeds the
algebraic sum of the Delta values obtained from integrator 9 on line 11. Similarly, flip-flop 7 generates Delta when the magnitude on
line 3 is less than the algebraic sum on line 11.

Tracking error "e" is representatively shown in Fig. 2 as the instantaneous
magnitude difference between the input signal and the integrated output signal.
So that there will be no ambiguity, the signals labeled Delta or Delta represent
sequences of 1's and 0's in the digital sense, and also refer to magnitude values
generated by flip-flop 7 when applied to integrator 9.

Referring to Fig. 2, there is shown the tracking by the delta coder of the time
varying analog input over a succession of sa...